Electric-motor system.



No.- 727,684. PATENTED MAY-12,1903.

w. B. POTTER. ELECTRIC MOTOR SYSTEM.

APPLICATION FILED 001. 31, 1900.

H0 HODEL.

Fig. 1 D E Fig. 5.

Witnesses V I Inventor:

William B. Potter".

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UNITED STATES Patented May 12, 1903.

PAT T OFFICE.

WILLIAM B. POTTER, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC-MOTOR SYSTEM.

SPECIFICATION formingpart of Letters Patent No. 727,684, dated May 12,1903. Application filed October 31,1900. Serial No. 34.997. (No model.)

To aZZ whom, it may concern:

Beit known that I, WILLIAM B. POTTER, a citizen of the UnitedStates,residing at Schen ectady, county of Schenectady, State of NewYork, have invented certain new and useful Improvements inElectric-Motor Systems, of which the following is a specification.

My invention relates to motor systems, and has for one of its objects toprovide for using .0 a storage battery in place of the resistancescustomarily employed in connection with a motor-controller.

Furthermore, my invention enables amotor to be started by means of thebattery-cur- :5 rent only and afterward brought up to and maintained atfull speed by means of current taken from a main source of supply andopposed to the electromotive force of the battery, the direction of thecurrent through the motor being the same under both conditions.Moreover, the arrangement is such that as soon as the current from themain source is cut in it not only serves to drive the motor, but also torecharge the battery.

In the accompanying drawings, Figure l is a side elevation of anelectric-railway car provided with an overhead trolley and equipped withmy improved device for controlling the motor. Fig. 2 is a diagram of thecontroller connections, and Fig. 3 shows a modification of the same.

The car A is shown as provided with asingle motor B, connected withcontrollers C at each endof the car and taking current through a trolleyD from an overhead line conductor E, connected to a suit-able source ofsupply.

In Fig. 2 the field-magnet of the motor is shown at b and the armatureat b. versing-switch F, of the usual construction, is in circuit withthe motor and in connection with a stationary contact-finger c in thecontroller. The fingersc c c o are the termi nals of sections of astorage battery G. Finger c is connected with finger c and finger c isin circuit with the trolley D.

The controller-cylinder carries a grounded contact-plate c coacting withfinger c during the first three positions of the controller,

and a contact-plate c coacting with said finger during the last fourpositions of the controller. Parallel with these plates are twocontact-plates 0 0 connected together and with theplate 0 In the firstposition of the controller a contact-segment 0 coacts with the finger c.In the second position contactsegment 0 coacts with finger c and in thethird position contact-segment 0 with finger c, the segments e e and 0being electrically connected with each other and with the plate 0 In thefourth position of the controller contact-segment 0 coacts with finger 0in the fifth position contact-segment c with finger c in the sixthposition contact-segment c with finger c and in the seventh positioncontact-segment 0 with finger 0 A plate 0 makes contact with finger 0during the last four positions, said plate being connected With'all thesegments 0 0 0 and 0 It follows from this construction that in the firstposition one section of the battery is in circuit with the motor, in thesecond position two sections, and in the third position the entirebattery is discharging through the motor.

In the fourth position, however, the trolleycurrent,entering at thefinger c ,fiows through the battery in the opposite direction to thepath of discharge of said battery, passing out by Way of the plates 0and strip c and flowing through the motor in the same direction as thecurrent previously supplied by the battery. In this position the entireelectromotive force of the battery is opposed to the trolley-current, sothat a large percentage of the energy is consumed in recharging thebattery; but as the several portions of the battery are successively cutout by moving the controller-handle to positions 5, 6, and 7 more andmore of the trolley-current is utilized in the motor until in the lastposition 7 go the battery is entirely out of circuit and the motor isrunning with the full current from the trolley.

The potential of the storagebattery should be such that the movement ofthe controller 5 from position 3 to position 4 will increase the.potential at the motor-terminals by the same amount as the movement fromposition 2 to position 3, thereby securing a uniform acceleration of themotor. Evidently the con- :00

troller may have any desired number of operative positions and thebattery any desired number of sections.

In Fig. 2 the segments are so arranged as to open-circuit the batterybetween them; butthey may be arranged to overlap, as shown in Fig. 3,resistances H being introduced be tween the differentsegments to preventshortcircniting of the battery-cells affected by the transition.

Although I have hereinbefore described my invention as applied to asingle motor, yet it is equally applicable to a plurality of motors orto series-parallel control.

What I claim as new, and desire to secure by Letters Patent of theUnited States, is

1. The combination with an electric motor, of a main source of supplytherefor, a storage battery, and a controller constructed and arrangedto start the motor from the storage battery alone, then to throw themotor in circuit with the main source in series With the storagebattery, and finally to cut the storage battery out of circuit.

2. The combination With an electric motor, of a main source of supplytherefor, a s1 orage battery, and a controller constructed and ar rangedto connect the motor across a portion of the cells of the storagebattery to start the same, then to gradually cut the succeeding sectionsof the battery into the circuit, then to connect the motor in circuitwith the main source in series with the storage battery reverselyconnected, and finally to cut out the sections of the storage battery inthe reverse order in which they were out in.

3. The combination with an electric motor, of a source of current ofsubstantially constant potential, a storage battery, and a controllerconstructed and arranged to first connect the motor across a portion ofthe cells of the storage battery to start the motor, then to graduallyincrease the number of cells in the circuit until a predeterminedpotential at the motor-terminals is reached, then to connect the motorin circuit With the constant potential source in series with the storagebattery reversely connected, and finally to cut the said battery out ofcircuit.

In witness whereof I have hereunto set my hand this 29th day of October,1900.

WILLIAM B. POTTER.

WVitnesses:

BENJAMIN I HULL, MARGARET E. WooLLnY.

